The California director of the National Wildlife Federation is participating in a three-and-a-half day, 50-mile hike that follows the cougar's journey from the Santa Monica Mountains to Griffith Park.

The trek ends on Sunday, Oct. 22, also known as P-22 Day, an official Los Angeles holiday as of 2016.

To celebrate L.A.'s most famous cougar (sorry, Lisa Vanderpump), the city is hosting a free festival in Griffith Park on Sunday from 11 a.m. to 4 p.m. It's part of Urban Wildlife Week, which aims to make humans more aware of the animals in our urban ecosystem.

"These species need good quality habitat," David Mizejewski, naturalist at the National Wildlife Fund, tells KPCC. "Unfortunately, when we develop land we tend to eliminate that habitat, making it really hard for some of these species to continue to exist."

Freeways are especially problematic, as they can separate animals from their natural environs. P-22 is a perfect example. He lives in Griffith Park, essentially cut off from habitat, mates and food by the 101 and 405 freeways.

Crossing these thoroughfares is dangerous. His compatriot, P-32, was killed in 2015 trying to do that. A dozen big cats have been killed on roadways since scientists began tracking these stats in 2002, according to National Geographic.

The humans following in P-22's footsteps will cross both the 405 and the 101 — but they'll do it on bridges, unlike P-22. Pratt-Bergstrom's radio collar, the same model as the one the big cat wears, lets armchair conservationists follow the journey. (After the hike, she'll donate the collar so it can be placed on a cougar.)

"It is magical, doing this hike and seeing it through this cat's eyes. I am more admiring that he made it to Griffith Park. I don't know what spurred him on except a sense of adventure and obviously he needed to find a home. But wow, it's pretty cool doing it through his eyes," Pratt-Bergstrom tells KPCC.

Following the path of cougar P-22 during Urban Wildlife Week.

The National Wildlife Federation hopes the walk will raise awareness about the problems animals face in a sprawling metropolis — and boost one of their pet projects.

The organization wants the county to build North America's largest wildlife corridor, above the 101 Freeway in Agoura Hills. The overpass would allow cougars — and smaller mammals, amphibians, reptiles and other creatures — to cross from one side of the road to the other. Such a project is estimated to cost between $30 million and $60 million.

Sadly, it won't help P-22. He has already made his way across the highway, but for the rest of the mountain lion population in the Santa Monica Mountains, Mizejewski thinks it would be a critical resource.

Earlier this week, the Annenberg Foundation announced this week that it's offering to match all donations for the wildlife overpass up to $1 million.

"L.A. is home to one of the most diverse ecosystems in the world," said Annenberg Foundation executive director Cinny Kenard. "And so this was very attractive to the foundation to look at the way this particular issue impacts that."